Technology and mechanical properties of reinforced continuous fiber 3D-printed thermoplastic composite

Abstract

Background. Additive technologies based on Fused Deposition Modeling (FDM) modeling methods attract a lot of attention from both industry and research groups, which is explained by low investment costs, ease of production, etc. If the processing parameters are correctly selected, products with mechanical properties close to products obtained by traditional technologies can be obtained. Objective. Practical implementation of the modernized technology for 3D printing of Polylactid Acid (PLA) samples reinforced with continuous Kevlar fiber using the FDM method and determination of their mechanical properties. Methods is based on experimental and theoretical studies of the limit of tensile strength and modulus of elasticity of the composite and includes testing of samples on the SHIMADZU AGS-X testing machine and solving the inverse problem. Results. Experimental samples of thermoplastic composite (PLA+Kevlar fiber Æ0.3 mm) were tested for tension. It was found that the tensile strength of the reinforced composite compared to the unreinforced one with a Kevlar volume fraction of about 12% increases by 2.38 times, and the modulus of elasticity increases by 1.45 times. With a confidence interval of 0.68, the error of determining the ultimate tensile strength is 3.5%, and the modulus of elasticity is 4.5%. A theoretical dependence was obtained for predicting the modulus of elasticity of thermoplastic composites in the range of changes in the degree of reinforcement up to 15%. Conclusions. The application of additive technologies based on FDM for 3D printing of thermoplastic composites with increased mechanical properties is substantiated.